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Intravital imaging of a massive lymphocyte response in the cortical dura of mice after peripheral infection by trypanosomes.

Coles JA, Myburgh E, Ritchie R, Hamilton A, Rodgers J, Mottram JC, Barrett MP, Brewer JM - PLoS Negl Trop Dis (2015)

Bottom Line: Making use of optical signals from the skull bone, blood vessels and dural cells, we conclude that up to 40 dpi, the extravascular trypanosomes were essentially confined to the dura, as were the great majority of the T cells.Inhibition of T cell activation by intraperitoneal injection of abatacept reduced the numbers of meningeal T cells at 12 dpi and their mean speed fell from 11.64 ± 0.34 μm/min (mean ± SEM) to 5.2 ± 1.2 μm/min (p = 0.007).The population and motility of the trypanosomes tended to decline after about 30 dpi.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom; Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.

ABSTRACT
Peripheral infection by Trypanosoma brucei, the protozoan responsible for sleeping sickness, activates lymphocytes, and, at later stages, causes meningoencephalitis. We have videoed the cortical meninges and superficial parenchyma of C56BL/6 reporter mice infected with T.b.brucei. By use of a two-photon microscope to image through the thinned skull, the integrity of the tissues was maintained. We observed a 47-fold increase in CD2+ T cells in the meninges by 12 days post infection (dpi). CD11c+ dendritic cells also increased, and extravascular trypanosomes, made visible either by expression of a fluorescent protein, or by intravenous injection of furamidine, appeared. The likelihood that invasion will spread from the meninges to the parenchyma will depend strongly on whether the trypanosomes are below the arachnoid membrane, or above it, in the dura. Making use of optical signals from the skull bone, blood vessels and dural cells, we conclude that up to 40 dpi, the extravascular trypanosomes were essentially confined to the dura, as were the great majority of the T cells. Inhibition of T cell activation by intraperitoneal injection of abatacept reduced the numbers of meningeal T cells at 12 dpi and their mean speed fell from 11.64 ± 0.34 μm/min (mean ± SEM) to 5.2 ± 1.2 μm/min (p = 0.007). The T cells occasionally made contact lasting tens of minutes with dendritic cells, indicative of antigen presentation. The population and motility of the trypanosomes tended to decline after about 30 dpi. We suggest that the lymphocyte infiltration of the meninges may later contribute to encephalitis, but have no evidence that the dural trypanosomes invade the parenchyma.

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Related in: MedlinePlus

T cells and CD11c+ cells show some interaction with the vascular endothelium.A. A T cell (red, arrow) is almost stationary. B. The green blood marker image of the same frame confirms that the T cell was intravascular. C. 18 min later the T cell has moved only 2.5 μm. D. 20s after that it has moved out of the field. D,E,F. Frames at 2s intervals show a CD11c+ cell moving slowly (19.3 μm/s) in a blood vessel.
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pntd.0003714.g009: T cells and CD11c+ cells show some interaction with the vascular endothelium.A. A T cell (red, arrow) is almost stationary. B. The green blood marker image of the same frame confirms that the T cell was intravascular. C. 18 min later the T cell has moved only 2.5 μm. D. 20s after that it has moved out of the field. D,E,F. Frames at 2s intervals show a CD11c+ cell moving slowly (19.3 μm/s) in a blood vessel.

Mentions: Extravasation of leukocytes normally occurs by diapedesis, which takes several minutes and is preceded by a period of arrest on the vascular endothelium, which may last for hours [21, 55, 56]. Fluorescent T cells and dendritic cells were readily observed in meningeal blood vessels (Fig 9A and 9E). T cells were observed to attach to the vascular endothelium and crawl slowly (Fig 9A–9D). CD11c+ cells were not observed to crawl or halt, but, in rare cases, were observed to roll (Fig 9E and 9F). These rolling cells did not have a dendritic shape, and may have been macrophages. For neither cell type did we observe an unambiguous extravasation, but the prolonged interaction sometimes seen between T cells and vascular endothelium suggests that at least some of the extravascular T cells had arrived by classical diapedesis.


Intravital imaging of a massive lymphocyte response in the cortical dura of mice after peripheral infection by trypanosomes.

Coles JA, Myburgh E, Ritchie R, Hamilton A, Rodgers J, Mottram JC, Barrett MP, Brewer JM - PLoS Negl Trop Dis (2015)

T cells and CD11c+ cells show some interaction with the vascular endothelium.A. A T cell (red, arrow) is almost stationary. B. The green blood marker image of the same frame confirms that the T cell was intravascular. C. 18 min later the T cell has moved only 2.5 μm. D. 20s after that it has moved out of the field. D,E,F. Frames at 2s intervals show a CD11c+ cell moving slowly (19.3 μm/s) in a blood vessel.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4400075&req=5

pntd.0003714.g009: T cells and CD11c+ cells show some interaction with the vascular endothelium.A. A T cell (red, arrow) is almost stationary. B. The green blood marker image of the same frame confirms that the T cell was intravascular. C. 18 min later the T cell has moved only 2.5 μm. D. 20s after that it has moved out of the field. D,E,F. Frames at 2s intervals show a CD11c+ cell moving slowly (19.3 μm/s) in a blood vessel.
Mentions: Extravasation of leukocytes normally occurs by diapedesis, which takes several minutes and is preceded by a period of arrest on the vascular endothelium, which may last for hours [21, 55, 56]. Fluorescent T cells and dendritic cells were readily observed in meningeal blood vessels (Fig 9A and 9E). T cells were observed to attach to the vascular endothelium and crawl slowly (Fig 9A–9D). CD11c+ cells were not observed to crawl or halt, but, in rare cases, were observed to roll (Fig 9E and 9F). These rolling cells did not have a dendritic shape, and may have been macrophages. For neither cell type did we observe an unambiguous extravasation, but the prolonged interaction sometimes seen between T cells and vascular endothelium suggests that at least some of the extravascular T cells had arrived by classical diapedesis.

Bottom Line: Making use of optical signals from the skull bone, blood vessels and dural cells, we conclude that up to 40 dpi, the extravascular trypanosomes were essentially confined to the dura, as were the great majority of the T cells.Inhibition of T cell activation by intraperitoneal injection of abatacept reduced the numbers of meningeal T cells at 12 dpi and their mean speed fell from 11.64 ± 0.34 μm/min (mean ± SEM) to 5.2 ± 1.2 μm/min (p = 0.007).The population and motility of the trypanosomes tended to decline after about 30 dpi.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, United Kingdom; Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.

ABSTRACT
Peripheral infection by Trypanosoma brucei, the protozoan responsible for sleeping sickness, activates lymphocytes, and, at later stages, causes meningoencephalitis. We have videoed the cortical meninges and superficial parenchyma of C56BL/6 reporter mice infected with T.b.brucei. By use of a two-photon microscope to image through the thinned skull, the integrity of the tissues was maintained. We observed a 47-fold increase in CD2+ T cells in the meninges by 12 days post infection (dpi). CD11c+ dendritic cells also increased, and extravascular trypanosomes, made visible either by expression of a fluorescent protein, or by intravenous injection of furamidine, appeared. The likelihood that invasion will spread from the meninges to the parenchyma will depend strongly on whether the trypanosomes are below the arachnoid membrane, or above it, in the dura. Making use of optical signals from the skull bone, blood vessels and dural cells, we conclude that up to 40 dpi, the extravascular trypanosomes were essentially confined to the dura, as were the great majority of the T cells. Inhibition of T cell activation by intraperitoneal injection of abatacept reduced the numbers of meningeal T cells at 12 dpi and their mean speed fell from 11.64 ± 0.34 μm/min (mean ± SEM) to 5.2 ± 1.2 μm/min (p = 0.007). The T cells occasionally made contact lasting tens of minutes with dendritic cells, indicative of antigen presentation. The population and motility of the trypanosomes tended to decline after about 30 dpi. We suggest that the lymphocyte infiltration of the meninges may later contribute to encephalitis, but have no evidence that the dural trypanosomes invade the parenchyma.

Show MeSH
Related in: MedlinePlus